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Comparative evaluation of laser correction results in induced post-keratoplastic ametropia by FemtoLASIK and LASIK

Session Details

Session Title: Corneal Femtosecond

Session Date/Time: Monday 07/10/2013 | 14:30-16:30

Paper Time: 16:08

Venue: Elicium 1 (First Floor)

First Author: : A.Doga RUSSIA

Co Author(s): :    G. Kachalina   I. Mushkova   A. Karimova        

Abstract Details

Purpose:

To compare the results of FemtoLASIK and LASIK methods in an induced refractive error correction after penetrating keratoplasty (PKP)

Setting:

The S. Fyodorov Eye Microsurgery State Institution, Russia

Methods:

We observed 29 eyes (29 patients) with residual ametropy after the PKP in pre- and post-keratorefractive surgery, out of which 11 eyes were operated by the FemtoLASIK technology – group I, 18 eyes by the standard LASIK technology – group II. In both groups, the diameter of the corneal flap was calculated taking into account optometric parameters depending on the ablation zone and was independent of the graft diameter. The thickness of the flap was selected based on data of the central graft pachymetry and the degree of refractive error. Examination of the patients included, besides the standard refractive eye examinations, confocal microscopy and optical coherence tomography of anterior segment in the High Resolution Cornea mode.

Results:

After the keratorefractive surgery the spherical component decreased in the group I from -2.64±2.83 D to -0.25±0.61 D, in the group II from -2.67±3.06 D to -0.29±0.6 D. The average value of the cylindrical component also significantly decreased from 4.53±2.7 D to 1.23±1.64 D after the FemtoLASIK and from 4.48±2.72 D to 1.34±1.62 D after the LASIK (?<0.05). Uncorrected visual acuity compared with preoperative values significantly increased in the group I from 0.12±0.1 to 0.51±0.23, in the group II from 0.11±0.1 to 0.5±0.24. Loss of lines of corrected visual acuity was in no cases. The average deviation of the obtained thickness of the flap from the proposed using the femtosecond laser was 8.4±1.8 mm. In formation of corneal flap with a mechanical microkeratome was 23.4?3.8 mm. There was not a cutting of flap edge about 3 mm long during the FemtoLASIK in 2 eyes with a pronounced fibrosis in the area of the scar. In the group II epithelial defects were appeared during the formation of corneal flap with microkeratome and the removal of the vacuum ring in 6 eyes with changed epithelial cytoarchitectonic.

Conclusions:

Corneal flap formed by a femtosecond laser, is more uniformity and has less deviation in thickness than a flap formed with microkeratome. The graft fibrosis is contraindication for induced refractive error correction after the PKP by the FemtoLASIK. The FemtoLASIK and the LASIK are effective and safe technologies to achieve high functional results in the correction of induced ametropia in patients after the PKP.

Financial Interest:

NONE